The present invention relates to an engine-driven handheld vacuum/blower apparatus, and more particularly to a handgrip mechanism thereof.
The present application claims priority from Japanese Patent Application No. 2003-423186, the disclosure of which is incorporated herein by reference.
An engine-driven handheld vacuum/blower apparatus (hereinafter referred to as “vacuum/blower”) as shown, for example, in Japanese patent application laid-open No. Hei 10-205489 is known as one for collecting or gathering scattered lightweight rubbish such as fallen leaves on the ground through vacuuming or blowing with an engine-driven impeller.
The vacuum/blower of this type is usually held by operator's hands during the operation and thus required to include any configuration for grasping and holding it.
FIG. 11 shows one example of handgrips of a conventional engine-driven handheld vacuum/blower.
In FIG. 11, the vacuum/blower is oriented parallel to the ground. An impeller case 201 accommodating an impeller is coupled to an engine casing 200. A suction pipe 202 is connected to the impeller case 201 at a position corresponding to the rotation center of the impeller inside, and a blowpipe 203 is connected to the circumference of the impeller case 201 such as to extend in a tangential direction of the impeller.
On top of the engine casing 200 stands a first grip 200A, and a second grip 200B protrudes from near the center axis of the engine in a direction orthogonal to that of the first grip 200A.
The first grip 200A includes a throttle lever 200A1 and a stop switch 200A2. The operator grasps the first grip to hold the engine casing 200 in a suspended manner.
The second grip 200B is not held for supporting the engine casing 200 in a suspended manner but rather for supporting its weight while maintaining an inclined position of the engine casing 200 when, for example, the suction pipe 202 is oriented toward the ground.
In an operation where rubbish such as fallen leaves is collected using the suction pipe 202, when the engine casing 200 is inclined to orient the suction pipe 202 to the ground, the entire weight of the engine casing including the engine is mostly carried on the side of the second grip 200B which is nearer to the center axis G of the engine. This causes more hand fatigue on one hand grasping the second grip 200B than the other on the first grip 200A. The operator may have to stop the rubbish collecting operation to relieve the fatigue of the hand on the second grip 200B, resulting in poor work efficiency. Furthermore, because of the position of the second grip 200B extending perpendicularly to the first grip 200A, it is hard to form the second grip 200B in one piece with the engine casing 200 as with the first-grip 200A. Thus, the second grip 200B is usually manufactured as a separate part and attached to the engine casing 200 afterwards.
The structure according to the conventional technique thus led to poor work efficiency and high component and production costs.
The above mentioned Japanese patent application laid-open No. Hei 10-205489 shows an alternative arrangement of the handgrips on the engine casing. While the first grip is the same as that shown in FIG. 11, the second grip is formed as part of a stand which extends from a side face of the engine casing.
Another conventional structure is one as shown in Japanese patent application laid-open No. 2001-3761, which has a separate grip member attached on a fuel tank which is mounted on the engine casing.
In the case where the grip is formed as part of the stand, because the stand is provided as a separate component, a size reduction of the engine casing is not achieved. Furthermore, as long as the grip is part of the stand, a cost reduction is hard to achieve because of strength requirements of the stand such as material and size.
In the structure shown in Japanese patent application laid-open No. 2001-3761, because the grip is attached to the fuel tank which is mounted on the engine casing as a separate component, the engine casing with the fuel tank mounted thereon is inevitably bulky. In addition, there is a danger that heat from the engine casing may be transmitted to the grip through the fuel tank and the operator may suffer a burn on the hand after working with the vacuum/blower for a long time, because of which good workability is not expected.